'Foreskins' in the Bible

So Joshua made knives of flint, and he circumcised the {Israelites} at the hill of the foreskins.

Then Saul said, "This [is] what you must say to David: '{The king desires no bride price} except for a hundred foreskins of [the] Philistines, to avenge himself on the enemies of the king.'" (Now Saul had planned to allow David to fall by the hand of [the] Philistines.)

And David got up, and he and his men went and struck down two hundred men [of the] Philistines. Then David brought their foreskins, and {they presented the full number} to become the king's son-in-law. Then Saul gave him Michal his daughter as [his] wife.

Then David sent messengers to Ish-Bosheth the son of Saul, saying, "Give [me] my wife Michal whom I betrothed to myself for a hundred foreskins of [the] Philistines."

Circumcise yourselves to Yahweh, and remove the foreskins of your hearts, men of Judah and inhabitants of Jerusalem, lest my wrath goes forth like the fire and burns, and there is no [one who] extinguishes [it], because of the evil of your deeds."